TULSA, Okla. (AP) - An estimated 2,100 jobs could be lost at the American Airlines maintenance hub in Tulsa after mechanics rejected the company's final labor contract offer.

The Transport Workers Union said Tuesday that five of its work groups approved the company's offer. But its largest group, the mechanics, rejected the offer with 56 percent voting against. The union's store clerks group also voted "no."

American filed for bankruptcy protection in November and announced a plan in February to eliminate 13,000 union jobs as part of a cost-cutting move.

American has about 7,000 employees in Tulsa and is the largest private employer in the city. After the estimated layoffs, which still have to be approved by a bankruptcy court, the Tulsa hub could be down to about 4,700 employees.